<?php

require_once 'HTMLPurifier/AttrDef.php';

/**
 * Validates an IPv4 address
 * @author Feyd @ forums.devnetwork.net (public domain)
 */
class HTMLPurifier_AttrDef_URI_IPv4 extends HTMLPurifier_AttrDef
{
	
	/**
	 * IPv4 regex, protected so that IPv6 can reuse it
	 * @protected
	 */
	var $ip4;
	
	function validate($aIP, $config, &$context) {
		
		if (!$this->ip4) $this->_loadRegex();
		
		if (preg_match('#^' . $this->ip4 . '$#s', $aIP))
		{
				return $aIP;
		}
		
		return false;
		
	}
	
	/**
	 * Lazy load function to prevent regex from being stuffed in
	 * cache.
	 */
	function _loadRegex() {
		$oct = '(?:25[0-5]|2[0-4][0-9]|1[0-9]{2}|[1-9][0-9]|[0-9])'; // 0-255
		$this->ip4 = "(?:{$oct}\\.{$oct}\\.{$oct}\\.{$oct})";
	}
	
}

